To provide a combine harvester in which automatic control property of accelerator making a standard number of revolutions of engine changeable according to conditions is improved, compared with that of a conventional combine harvester even during setting of automatic control function of accelerator.

In the combine harvester, an accelerator automatic control means 200 can automatically set an accelerator opening of an engine 10 previously set every operation item such as reaping, threshing or discharging of grains to the outside, and when other operation item is set during operation in accordance with a time when a specific operation item is carried out, a function changeable into predetermined accelerator openings having a standard mode and energy-saving mode in accordance with both of the other operation item and the operation item during the operation is provided. As a result, when other operation item is set during operation in accordance to a time when a specific operation item is carried out, the accelerator opening is changeable to predetermined accelerator openings having standard mode and energy-saving mode in accordance to these two operation items to enable accelerator automatic control suitable for operation items.